Clinical evidence suggests that mood and behavioral symptoms in premenstrual dysphoric disorder (PMDD), a common, recently recognized, psychiatric condition among women, reflect abnormal responsivity to ovarian steroids. This differential sensitivity could be due to an unrecognized aspect of hormonal signaling or a difference in cellular response. In this study, lymphoblastoid cell line cultures (LCLs) from women with PMDD and asymptomatic controls were compared via whole-transcriptome sequencing (RNA-seq) during untreated (ovarian steroid-free) conditions and following hormone treatment. The women with PMDD manifested ovarian steroid-triggered behavioral sensitivity during a hormone suppression and addback clinical trial, and controls did not, leading us to hypothesize that women with PMDD might differ in their cellular response to ovarian steroids. In untreated LCLs, our results overall suggest a divergence between mRNA (for example, gene transcription) and protein (for example, RNA translation in proteins) for the same genes. Pathway analysis of the LCL transcriptome revealed, among others, over-expression of ESC/E(Z) complex genes (an ovarian steroid-regulated gene silencing complex) in untreated LCLs from women with PMDD, with more than half of these genes over-expressed as compared with the controls, and with significant effects for MTF2, PHF19 and SIRT1 (P<0.05). RNA and protein expression of the 13 ESC/E(Z) complex genes were individually quantitated. This pattern of increased ESC/E(Z) mRNA expression was confirmed in a larger cohort by qRT-PCR. In contrast, protein expression of ESC/E(Z) genes was decreased in untreated PMDD LCLs with MTF2, PHF19 and SIRT1 all significantly decreased (P<0.05). Finally, mRNA expression of several ESC/E(Z) complex genes were increased by progesterone in controls only, and decreased by estradiol in PMDD LCLs. These findings demonstrate that LCLs from women with PMDD manifest a cellular difference in ESC/E(Z) complex function both in the untreated condition and in response to ovarian hormones. Dysregulation of ESC/E(Z) complex function could contribute to PMDD. We further investigated the association between PMDD and abnormal responsivity to ovarian steroids. This differential steroid sensitivity could be underpinned by abnormal processing of the steroid signal. We used a pharmacometabolomics approach in women with prospectively confirmed PMDD (n=15) and controls without menstrual cycle-related affective symptoms (n=15). All were medication-free with normal menstrual cycle lengths. Notably, women with PMDD were required to show hormone sensitivity in an ovarian suppression protocol. Ovarian suppression was induced for 6 months with gonadotropin-releasing hormone (GnRH)-agonist (Lupron); after 3 months all were randomized to 4 weeks of estradiol (E2) or progesterone (P4). After a 2-week washout, a crossover was performed. Liquid chromatography/tandem mass spectrometry measured 49 steroid metabolites in serum. Values were excluded if >40% were below the limit of detectability (n=21). Analyses were performed with Wilcoxon rank-sum tests using false-discovery rate (q<0.2) for multiple comparisons. PMDD and controls had similar basal levels of metabolites during Lupron and P4-derived neurosteroids during Lupron or E2/P4 conditions. Both groups had significant increases in several steroid metabolites compared with the Lupron alone condition after treatment with E2 (that is, estrone-SO4 (q=0.039 and q=0.002, respectively) and estradiol-3-SO4 (q=0.166 and q=0.001, respectively)) and after treatment with P4 (that is, allopregnanolone (q=0.001 for both PMDD and controls), pregnanediol (q=0.077 and q=0.030, respectively) and cortexone (q=0.118 and q=0.157, respectively). Only sulfated steroid metabolites showed significant diagnosis-related differences. During Lupron plus E2 treatment, women with PMDD had a significantly attenuated increase in E2-3-sulfate (q=0.035) compared with control women, and during Lupron plus P4 treatment a decrease in DHEA-sulfate (q=0.07) compared with an increase in controls. Significant effects of E2 addback compared with Lupron were observed in women with PMDD who had significant decreases in DHEA-sulfate (q=0.065) and pregnenolone sulfate (q=0.076), whereas controls had nonsignificant increases (however, these differences did not meet statistical significance for a between diagnosis effect). Alterations of sulfotransferase activity could contribute to the differential steroid sensitivity in PMDD. Importantly, no differences in the formation of P4-derived neurosteroids were observed in this otherwise highly selected sample of women studied under controlled hormone exposures. We investigated whether PMDD symptoms could be precipitated either by an acute change in ovarian steroid levels or by stable levels above a critical threshold playing a permissive role in expression of an underlying infradian affective pacemaker. The study included 22 women with PMDD, ages 30 to 50 years. Twelve women who experienced symptom remission after 2-3 months of GnRH agonist-induced ovarian suppression (leuprolide) then received 1 month of single-blind (participant only) placebo and then 3 months of continuous combined estradiol/progesterone. Primary outcome measures were the Rating for Premenstrual Tension observer and self-ratings completed every 2 weeks during clinic visits. Multivariate repeated-measure ANOVA for mixed models was employed. Both self- and observer-rated scores on the Rating for Premenstrual Tension were significantly increased (more symptomatic) during the first month of combined estradiol/progesterone compared with the last month of leuprolide alone, the placebo month, and the second and third months of estradiol/progesterone. There were no significant differences in symptom severity between the last month of leuprolide alone, placebo month, or second and third months of estradiol/progesterone. Finally, the Rating for Premenstrual Tension scores in the second and third estradiol/progesterone months did not significantly differ. Thus, the change in estradiol/progesterone levels from low to high, and not the steady-state level, was associated with onset of PMDD symptoms. Therapeutic efforts to modulate the change in steroid levels proximate to ovulation merit further study.